Tight-binding model calculation of surface optical response.

Abstract

We derive and evaluate a tight-binding model of surface optical response. Both one- and two-band models of the electronic structure are considered and the interactions between intraband and interband responses are consistently treated in a calculation of d parameters. The theory combines features of both jellium and dipolium models and allows one to extend each towards a common middle ground. Simple continuum model estimates are also developed which crudely describe the discrete-lattice effects. A series of model calculations illustrate various qualitative aspects of the optical response. The possibilities for future refinements and adaptations to describe real materials are briefly discussed.